The Information Commissioner's Office is looking into an alleged breach of the Data Protection Act after the West Yorkshire branch of the Gay Police Association (WYGPA) mistakenly leaked names and email addresses to around 100 people signed up to an LGBT mailing list.

The Register was first alerted to the email gaffe by an eagle-eyed reader who spotted a student doctor complaining about it on Twitter.

"Just received an email from West Yorkshire Police LGBT Association which discloses the email addresses of everyone on their mailing list," said Jacob Lovie on the microblogging site.

"Everyone has been CC'd. I'm in a little bit of shock. It's their entire LGBT mailing list."

He added: "Surely that's in breach of the data protection act? What if any of those people aren't out? Terrible."

However, when El Reg first contacted the West Yorkshire Police, we were surprised by the force's gay police association's initial response to the data-handling cockup.

A spokesman for the West Yorkshire GPA said:

We are aware of this issue in which an email asking for volunteers was sent to interested parties with the addresses listed in the 'cc' field and not the 'bcc' field.

The list to which the email was sent was a community contact list of email addresses volunteered to the West Yorkshire Gay Police Association at Pride events in 2011, for the purpose of circulating information about community projects, events, recruitment or volunteering.

Those emailed were not members of the WYGPA, and had provided their email addresses when attending a public event and indicated they wanted to be contacted with information and news, such as the contents of this email.

No confidential information was disclosed and no other details other than the email addresses of those individuals are held by us, and these email addresses are retained solely by the WYGPA.

We would like to take this opportunity to sincerely apologise to anyone who is concerned by this mistake, which was made innocently, and we would like to assure everyone that steps have been taken to ensure that the same mistake will not happen again.

We pressed the WYGPA for more details about the data blunder and asked several times if it would be informing the ICO of a potential breach.

Late on Friday the WYPGA finally told us that it would be contacting the UK's data watchdog "at the earliest opportunity" and added that the matter had been reported to the force's professional standards department.

the group further confirmed that the mailing list in question contained around 160 email addresses, with around 60 messages bouncing back to the sender.

The ICO said it had "recently been made aware of this possible breach", and added that it would "be making enquiries into the circumstances of the alleged breach of the Data Protection Act before deciding what action, if any, needs to be taken".

West Yorkshire Police separately spoke with Jacob Lovie about the data leak. He later tweeted: "Just got off the phone wit[h] West Yorkshire Police, everyt[h]ing has been sorted and they've sent an apology email out. #Impressed." ®